Qualitative and quantitative evaluation of phenolic compounds in Iris dichotoma Pall

Introduction: The rhizome of Iris dichotoma Pall., a traditional Chinese herbal medicine that contains (iso) Flavonoids as the main bioactive compound, has been used to treat several disorders such as inflammation, throat disorders, asthma and coughs. However, there is a lack of suitable methods for its qualitative and quantitative analysis as well as quality control.

Objectives: To establish an HPLC method for the simultaneous determination of phenolic constituents, the identification of characteristic metabolites in the rhizomes of I. dichotoma and to compare their contents in samples from different areas of China.

Methodology: HPLC coupled with diode-array detection (DAD) and electrospray ionisation multistage mass spectrometry (ESI-MS(n) ), and principal component analysis (PCA) were used for the qualitative and quantitative analysis of phenolic compounds in I. dichotoma samples.

Results: Twenty characteristic compounds were identified or tentatively characterised. A quantitative HPLC-UV method allowing the simultaneous quantification of 10 phenolic compounds was optimised and validated in terms of linearity, precision, accuracy, and limits of detection and quantification.

Conclusion: The methodology developed proved to be effective for the identification and quantification of phenolic compounds in the rhizomes of I. dichotoma. Samples were classified into three groups according to their geographical origin based on their phenolic composition using principal component analysis.